Sign up to receive free email alerts when patent applications with chosen keywords are publishedSIGN UP

Abstract:

An image reading device includes: an original table having a stationary
original reading area and a moving original reading area on its top
surface; an image reading unit provided inside the original table and
moving the reading line in the direction of the width of the stationary
original reading area and to the moving original reading area with the
direction of the length of the stationary original reading area as the
reading line; an original cover openably and closably provided on the
original table so as to cover at least the stationary original reading
area; and an ADF having an original conveyance path leading from an
original tray by way of the moving original reading area to an original
output tray. The image reading device reads originals of sizes larger
than the readable stationary original size without any size increase of
the device.

Claims:

1. An image reading device comprising: an original table including a
first area in which an image on a stationary original is configured to be
read and a second area in which an image on a moved original is
configured to be read; an operational panel disposed on a first side of
the image reading device; an original placement portion; an original
output portion; and an auto document feeder separately and independently
provided adjacent to the operational panel, and having a U-turn path
which extends from the original placement portion, by way of the second
area, to the original output portion, the original output portion being
provided adjacent to the auto document feeder and extending toward a
second side, opposite to the first side of the image reading device.

2. The image reading device according to claim 1, wherein each of the
first area and the second area has a transparent portion exposed from a
top surface of the original table, each exposed portion having a
rectangular shape.

3. The image reading device according to claim 2, wherein the
longitudinal direction of each exposed portion coincides with each other.

4. The image reading device according to claim 1, wherein the second area
is provided between the first area and the operational panel.

5. The image reading device according to claim 1, further comprising a
cover member openably and closably provided on the original table, the
cover member being attached through hinges on the second side of the
original table.

6. The image reading device according to claim 5, wherein the auto
document feeder is integrated with the cover member.

7. The image reading device according to claim 5, further comprising an
extension tray provided on the cover member, wherein the extension tray
is pivotably supported on the second side of the image reading device.

8. The image reading device according to claim 1, wherein the original
output portion is provided above the original placement portion, and the
image surface of an outputted original faces upwardly when the image
surface of the original is placed downwardly on the original placement
portion.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional of prior U.S. application Ser. No.
11/512,422, filed Aug. 30, 2006, which claims priority under 35 U.S.C.
§119(a) on Patent Application No. 2005-248830 filed in Japan on Aug.
30, 2005, the entire contents of which are hereby incorporated by
reference.

BACKGROUND

[0002] The present invention relates to an image reading device capable of
image reading from a stationary original and image reading from a moving
original.

[0003] Conventionally, image reading devices have been known that are
capable of image reading from a stationary original and image reading
from a moving original. Image reading from a stationary original is
performed by reciprocating an image sensor with respect to a platen glass
where the original is placed. Such image reading is known, for example,
as an image reading device called a flatbed type. On the other hand, to
perform image reading from a moving original, the original is conveyed to
the reading position of the image sensor by an original conveying
mechanism that conveys the original along a predetermined conveyance
path, and image reading is performed when the original passes through the
reading position. As such an original conveying mechanism, for example,
one called an auto document feeder (hereinafter, referred to as "ADF") is
known.

[0004] FIGS. 1 and 2 are perspective views showing a conventional image
reading device capable of image reading from a stationary original and
image reading from a moving original. A multi function device (MFD) 90
integrally comprises a printer unit 91 below and a scanner unit 92 above,
and has a printer function, a scanner function, and a copier function.
The scanner unit 92 of the multi function device 90 is an image reading
device that performs image reading from a stationary original and image
reading from a moving original.

[0005] In the scanner unit 92, an original cover 94 is openably and
closably provided on an original table 93. A platen glass 95 is disposed
on the top surface of the original table 93. When a stationary original
is read, the original is placed on the platen glass 95. An image reading
unit having an image sensor is provided inside the original table 93. As
the image sensor, for example, a contact image sensor (hereinafter,
referred to as "CIS") is used. By this image sensor being moved parallel
to the platen glass 95, image reading from the original placed on the
platen glass 95 is performed.

[0006] As shown in FIG. 1, the original cover 94 has an ADF 96. The ADF 96
conveys the original along a predetermined conveyance path from an
original tray 97 to an output tray 98. These two trays are disposed one
on the other on the top surface of the original cover 94. As shown in
FIG. 2, an opening 99 for reading a moving original is formed on the
lower surface of the original cover 94. The original conveyed along the
conveyance path of the ADF 96 is exposed to the platen glass 95 when
passing through the opening 99. A partial area of the platen glass 95
opposed to the opening 99 when the original cover 94 is closed is a
reading surface for reading a moving original. When a moving original is
read, the image sensor is stopped below the reading surface. Then, the
image of the original passing through the opening 99 while being conveyed
by the ADF 96 is read by the image sensor.

[0007] The CIS used as the image sensor is moved in a direction orthogonal
to a reading line with one direction of the platen glass 95, that is, the
direction of the width or the depth of the platen glass 95 as the reading
line. In the scanner unit 92, to read the original passing through the
opening 99 by the ADF 96, the image sensor is disposed so that the same
direction as the direction of the length of the opening 99, that is, the
direction of the depth of the platen glass 95 is the reading line. On the
other hand, in image reading devices of the flatbed type not having the
ADF, the image sensor is sometimes disposed so that the direction of the
length of the platen glass is the reading line (see, for example,
Japanese Patent Application Laid-Open No. 2002-290680).

SUMMARY

[0008] In image reading devices of the flatbed type that perform image
reading from a stationary original, it is necessary that all the area of
the original to be read be on the image reading area of the platen glass.
In other words, in image reading devices of the flatbed type, image
reading cannot be performed from the part of the original that lies
outside the image reading area of the platen glass. Therefore, the size
of the platen glass coincides with the maximum original size that can be
read. For example, the platen glass used for image reading devices whose
maximum readable size is A3 size has an area slightly larger than A3
size. On the other hand, the platen glass used for image reading devices
whose maximum readable size is A4 size has an area slightly larger than
A4 size.

[0009] It is demanded that MFDs having the printer function, the scanner
function, the copier function, and the like be multifunctional and
small-sized. Therefore, many scanner units used for MFDs adopt, as the
maximum readable size, A4 size the frequency of use of which is
comparatively high. Images read by image reading devices are easy to be
enlarged and reduced by using an image processing program or the like.
Therefore, it can be performed to reduce an image read by the scanner
unit of the MFD and print it in an arbitrary layout on a sheet of a
desired size. Considering such a function, it is convenient if an image
larger than A4 size can be read by the scanner unit even if the maximum
reading sheet size that can be printed by the printer unit is A4 size.

[0010] The present invention is made in view of such circumstances, and an
object thereof is to provide an image reading device capable of reading
originals of sizes larger than the readable stationary original size
without any size increase of the image reading device.

[0011] An image reading device is provided with: an original table having
a stationary original reading area that is rectangular when viewed
two-dimensionally and where a transparent member is exposed from a top
surface thereof and a moving original reading area where the transparent
member is exposed along a direction of a length of the stationary
original reading area; a line sensor provided inside the original table,
and moving a reading line in a direction of a width of the stationary
original reading area and to the moving original reading area with the
direction of the length of the stationary original reading area as the
reading line; a cover member openably and closably provided on the
original table so as to cover at least the stationary original reading
area; and an original conveying mechanism having a conveyance path
leading from an original placement portion where an original to be read
is placed by way of the moving original reading area in a direction
orthogonal to a direction of a length of the moving original reading area
to an original output portion where the original is outputted.

[0012] The stationary original reading area that is rectangular when
viewed two-dimensionally and the moving original reading area formed
along the direction of the length of the stationary original reading area
are formed on the top surface of the original table. The original from
which image reading is performed is placed on the stationary original
reading area. The line sensor provided inside the original table reads
the image of the original by moving its reading line in the direction of
the width of the stationary original reading area with the direction of
the length of the stationary original reading area as the reading line.
That is, the direction of the length of the stationary original reading
area is the main scanning direction of the line sensor, and the direction
of the width thereof is the sub scanning direction of the line sensor.
Thereby, image reading from originals of sizes that can be placed on the
stationary original reading area is performed.

[0013] The original conveying mechanism conveys the original placed on the
original placement portion by way of the moving original reading area to
the original output portion. In the moving original reading area, the
original is conveyed in the direction orthogonal to the direction of the
length thereof. The line sensor is situated below the moving original
reading area, and the image of the original passing through the moving
original reading area is read. The moving original reading area is formed
along the direction of the length of the stationary original reading
area, and the direction of the length of the stationary original reading
area is the same as the direction of the reading line of the line sensor.
That is, the direction of the length of the moving original reading area
is the main scanning direction of the line sensor, and the conveyance
direction is the sub scanning direction of the line sensor. Thereby,
image reading from originals of widths that lie within the length of the
moving original reading area is performed.

[0014] In such an image reading device, the stationary original reading
area that is rectangular when viewed two-dimensionally and the moving
original reading area formed along the direction of the length of the
stationary original reading area are formed on the top surface of the
original table, and the line sensor provided inside the original table
performs image reading from the original placed on the stationary
original reading area with the direction of the length of the stationary
original reading area as the main scanning direction and the direction of
the width thereof as the sub scanning direction. Thereby, the movement
width of the reading line of the line sensor with respect to the
stationary original reading area is reduced. Moreover, since in the
moving original reading area, the original is conveyed by the original
conveying mechanism in the direction orthogonal to the direction of the
length of the moving original reading area and image reading from the
conveyed original is performed with the direction of the length of the
moving original reading area as the main scanning direction of the line
sensor and the conveyance direction as the sub scanning direction, image
reading from originals of widths that lie within the length of the moving
original reading area is performed. Thereby, image reading from originals
of large sizes that cannot be placed on the stationary original reading
area can be performed.

[0015] The above and further objects and features of the invention will
more fully be apparent from the following detailed description with
accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0016]FIG. 1 is a perspective view showing the external structure of the
multi function device having the conventional image reading device;

[0017] FIG. 2 is a perspective view showing the external structure of the
multi function device having the conventional image reading device;

[0018]FIG. 3 is a perspective view showing the external structure of an
image reading device according to a first embodiment;

[0019]FIG. 4 is a perspective view showing the image reading device in a
condition where an original cover is opened with respect to an original
table;

[0020]FIG. 5 is a plan view showing the internal structure of the
original table;

[0021] FIG. 6 is a plan view showing the structure of a CIS;

[0022]FIG. 7 is a plan view showing the structure of a carriage provided
with the CIS;

[0023]FIG. 8 is a longitudinal cross-sectional view showing the internal
structure of the original table;

[0024] FIG. 9 is a plan view showing the structure of a belt driving
mechanism;

[0025]FIG. 10 is a longitudinal cross-sectional view showing the
principal structure of an ADF;

[0026] FIG. 11 is a plan view for explaining the image reading operation
in a stationary original reading area;

[0027] FIG. 12 is a plan view for explaining the image reading operation
in a moving original reading area;

[0028]FIG. 13 is a longitudinal cross-sectional view showing the
principal structure of an ADF;

[0029]FIG. 14 is a perspective view showing the external structure of an
image reading device according to a second embodiment;

[0030] FIG. 15 is a perspective view showing the image reading device in a
condition where an original cover is opened with respect to an original
table;

[0031] FIG. 16 is a plan view for explaining the image reading operation
in a stationary original reading area; and

[0032]FIG. 17 is a plan view for explaining the image reading operation
in a moving original reading area.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0033] Hereinafter, the present invention will be described in detail with
reference to the drawings showing embodiments thereof. It is to be noted
that the embodiments shown below are merely examples and may be modified
as appropriate without departing from the scope of the invention.

First Embodiment

[0034]FIG. 3 is a perspective view showing the external structure of an
image reading device 1 according to a first embodiment. In the image
reading device 1, an original cover 4 (cover member) having an ADF 3 is
openably and closably attached through hinges on the back side to an
original table 2 functioning as an FBS (flatbed scanner).

[0035] An operation panel 5 is provided on the front side of the image
reading device 1. The operation panel 5 has various operation keys and a
liquid crystal display. A user inputs a desired instruction by using the
operation panel 5. The image reading device 1 performs a predetermined
operation in response to a predetermined input. The image reading device
1 operates not only on instructions inputted to the operation panel 5 but
also on instructions transmitted, when the image reading device 1 is
connected to a computer, from the computer through a scanner driver.

[0036] The image reading device 1 is mainly connected to a non-illustrated
computer, and transfers the read image data to the computer. It is to be
noted that the image reading device 1 is merely an embodiment and may be
implemented, for example, as the scanner unit in an MFD having the
printer function, the scanner function, the copier function, and the
like, or as the image reading unit of a copier.

[0037]FIG. 4 shows the image reading device 1 in a condition where the
original cover 4 is opened with respect to the original table 2. As shown
in the figure, a platen glass 20 (transparent member) is disposed on the
top surface of the original table 2. The area where the platen glass 20
is exposed from the top surface of the original table 2 is a stationary
original reading area 22 and a moving original reading area 23. The
stationary original reading area 22 is an area where the original is
placed and read when the image reading device 1 is used as a flatbed
scanner. The moving original reading area 23 is an area where the
original passes when image reading is performed by using the ADF 3 of the
image reading device 1.

[0038] The stationary original reading area 22 is rectangular when viewed
two-dimensionally, and occupies most of the top surface of the original
table 2. The direction of the length of the stationary original reading
area 22 is the direction of the width of the device. The maximum size
that can be placed on the stationary original reading area 22 is A4 size.
That is, when used as an FBS, the image reading device 1 can read
originals of up to A4 size. An A4-size original is placed on the platen
glass 20 so that the direction of the length thereof coincides with the
direction of the length of the stationary original reading area 22, that
is, with the direction of the length of the original as the direction of
the width of the device.

[0039] The moving original reading area 23 is formed on the device front
side of the stationary original reading area 22 on the top surface of the
original table 2. The moving original reading area 23 is an area
elongated in the direction of the length of the stationary original
reading area 22. When image reading is performed by using the ADF 3 of
the image reading device 1, the original is conveyed so as to pass
through the moving original reading area 23.

[0040] When the original cover 4 is closed as shown in FIG. 3, the
stationary original reading area 22 and the moving original reading area
23 are covered with the original cover 4. To press the original placed on
the stationary original reading area 22, a pressing member 21 comprising
a sponge, a white board and the like is disposed on the lower surface of
the original cover 4.

[0041] An image reading unit 24 is incorporated in the original table 2.
In the image reading by the FBS, the image reading unit 24 is
reciprocated along the platen glass 20 to thereby perform image reading
from the original placed on the stationary original reading area 22. When
the ADF 3 is used, the image reading unit 24 moves to a position where
the original passing through the moving original reading area 23 can be
read, and stops.

[0042]FIG. 5 is a plan view showing the internal structure of the
original table 2, and depicts a condition where an upper cover 26 (see
FIG. 8) of the casing of the original table 2 is detached. The image
reading unit 24 is disposed within a lower frame 25 of the casing of the
original table 2. The upper cover 26 where an opening for exposing the
platen glass 20 is formed is joined to the lower frame 25 to thereby
constitute the casing of the original table 2. The lower frame 25 and the
upper cover 26 are both made of a synthetic resin. The lower frame 25 has
a partition plate for partitioning into a part where the image reading
unit 24 is disposed and a part where the board of the operation panel 5
and the like are disposed, supporting ribs for supporting the platen
glass 20, bosses for screwing various members, and through holes for
electrical wiring, and these components are omitted in FIGS. 5 and 6
since they are designed as appropriate according to the embodiment of the
original table 2.

[0044] FIG. 6 is a plan view showing the structure of the CIS 27. As shown
in FIG. 6, the CIS 27 has a casing 32 the general shape of which is an
elongated rectangular parallelepiped and the top surface 31 of which is
an elongated plane being rectangular when viewed two-dimensionally. On
the top surface 31 of the casing 32, a light guide 33 that guides the
light of the LED incorporated in the casing 32 is disposed in the
direction of the length of the casing 32 substantially at the same width.
The light guide 33 makes the light of the LED exit in the direction of
the length toward the top surface 31 of the casing 32 of the CIS 27. On
the top surface 31 of the casing 32, a plurality of condenser lenses 34
are arranged in a row in the direction of the length of the casing 32
substantially at the same width so as to be parallel to the light guide
33. Inside the casing 32, a plurality of light receiving elements are
arranged in a row immediately below the condenser lenses 34 in the same
direction as that of the condenser lenses 34 substantially at the same
width as that of the casing 32. The light emitted from the LED is applied
to the original on the platen glass 20, and the light reflected therefrom
is condensed on the light receiving elements by the condenser lenses 34.
The light receiving elements are so-called photoelectric conversion
elements that output an electric signal responsive to the intensity of
the reflected light, and output an electric signal responsive to the
reflected light intensity. The direction of the length of the casing 32
of the CIS 27 is the main scanning direction in image reading. The length
in the main scanning direction, that is, the length in the direction of
the length of the casing 32 of the CIS 27 is a length corresponding to a
medium to be read of the maximum size that can be read by the CIS 27. The
CIS 27 performs image reading with the direction of the length of the
casing 32 as the reading line, and outputs an electric signal for each
reading line.

[0045] Positioning portions 35 are provided on the casing 32 of the CIS
27. The positioning portions 35 perform positioning in the sub scanning
direction of the CIS 27, that is, in the direction orthogonal to the main
scanning direction with respect to the carriage 28. The positioning
portions 35 each have a base 36 provided so as to protrude from one end
in the direction of the width of the casing 32 of the CIS 27 and a shaft
37 provided so as to protrude from the base 36 in the direction of the
length. The shafts 37 engage with bearings 41 of the carriage 28
described later for positioning in the sub scanning direction of the CIS
27. A convex portion 38 is formed on the other end in the direction of
the width of the casing 32 of the CIS 27. The convex portion 38 is fitted
in a concave portion 42 of the carriage 28 described later for
positioning in the main scanning direction of the CIS 27.

[0046]FIG. 7 is a plan view showing the carriage 28 provided with the CIS
27. As shown in FIG. 7, the carriage 28 has a container shape on the top
surface of which the CIS 27 is mounted. The carriage 28 has a bottom 39
(see FIG. 8) and walls 40 provided so as to rise upward from both ends in
the sub scanning direction of the bottom 39. The CIS 27 is housed in a
space defined by the bottom 39 and the walls 40. No wall is provided on
both ends in the main scanning direction of the bottom 39, and one end of
the casing 32 of the CIS 27 protrudes from the side of the direction of
the length of the carriage 28. The top end of the carriage 28 is open,
and the top surface 31 of the CIS 27 mounted on the carriage 28 is
exposed.

[0047] The bearings 41 engaged with the positioning portions 35 of the CIS
27 are formed on one of the walls 40. The bearings 41 are elongated holes
that are vertical when the direction toward the bottom 39 is regarded as
downward, and the shafts 37 of the positioning portions 35 are inserted
into the elongated holes to thereby engage the positioning portions 35
and the bearings 41 with each other. The bearings 41 are disposed in
positions corresponding to the pair of positioning portions 35. The
concave portion 42 is formed on the inner surface of the other of the
walls 40 so as to correspond to the convex portion 38. The concave
portion 42 and the convex portion 38 of the CIS 27 engage with each other
for positioning, in the main scanning direction, of the CIS 27 with
respect to the carriage 28.

[0048] While in the present embodiment, the positioning in the sub
scanning direction is performed by the positioning portions 35 provided
on the casing 32 of the CIS 27 and the positioning in the main scanning
direction is performed by the convex portion 38, the positioning of the
CIS 27 with respect to the carriage 28 by these portions is merely an
example, and the configuration, the positioning direction and the like
may be modified.

[0049] A roller unit 43 is provided on each end in the direction of the
length of the CIS 27. As shown in FIG. 6, a positioning hole 44 for
positioning of the roller unit 43 is provided on each end of the top
surface 31 of the CIS 27. Pins provided in a protruding condition on the
bottom surface of the roller units 43 are inserted in the positioning
holes 44 to thereby position and fix the roller units 43 at both ends of
the CIS 27 as shown in FIG. 7. In each roller unit 43, a pair of rollers
46 is supported by a frame 45 so that they can roll in the direction of
the width of the CIS 27. The rollers 46 evenly protrude from the top
surface 31 of the CIS 27, and the gap between the top surface 31 of the
CIS 27 and the lower surface of the platen glass 20 is maintained
constant by the rollers 46 abutting on the lower surface of the platen
glass 20. The rolling of the rollers 46 makes smooth the movement of the
CIS 27 with respect to the platen glass 20.

[0050]FIG. 8 is a longitudinal cross-sectional view showing the internal
structure of the original table 2. As shown in FIG. 8, the carriage 28 is
provided with the CIS 27 so as to support it on the upper side thereof. A
shaft bearing 47 engaged so as to be fitted on the guide shaft 29 from
above is formed on the lower surface of the carriage 28. The shaft
bearing 47 and the guide shaft 29 engage with each other to thereby
support the carriage 28 on the guide shaft 29, and the carriage 28 is
slidable in the axial direction of the guide shaft 29. A belt grasping
portion 48 protrudes downward on a side of the shaft bearing 47. When the
belt grasping portion 48 grasps a timing belt 53 of the belt driving
mechanism 30, the timing belt 53 and the carriage 28 are coupled
together. Thereby, the driving force is transmitted from the belt driving
mechanism 30 to the carriage 28, so that the carriage 28 moves on the
guide shaft 29.

[0051] A spring bearing 49 is formed in two positions on the right and
left on the inner surface of the carriage 28. Coil springs 50, which are
positioned by the spring bearings 49, are interposed between the CIS 27
and the carriage 28. The coil springs 50 bring the CIS 27 mounted on the
carriage 28 into close contact with the lower surface of the platen glass
20 so as to be pressed thereagainst through the roller units 43. The CIS
27 is movable vertically with respect to the carriage 28 by an elastic
deformation of the coil springs 50. Therefore, when the platen glass 20
bends, the CIS 27 vertically moves so as to follow the bending.

[0052] FIG. 9 is a plan view showing the structure of the belt driving
mechanism 30, and depicts a condition where the upper cover 26, the
carriage 28 and the like of the casing of the original table 2 are
detached. As shown in FIG. 9, in the belt driving mechanism 30, the
timing belt 53 is entrained around a driving pulley 51 and a driven
pulley 52. The timing belt 53 is an endless belt having teeth on the
inside thereof. The rotation of the motor is outputted to the shaft of
the driving pulley 51. Receiving the rotation of the driving pulley 51,
the timing belt 53 moves circumferentially. The driving pulley 51 is
disposed on the left on the front side of the lower frame 25. The timing
belt 53 wound around the driving pulley 51 is extended to the vicinity of
the center along the front side of the lower frame 25, is bent
substantially at the right angle by being wound on an intermediate pulley
54 disposed upstream from the guide shaft 29, and is extended to the back
surface of the lower frame 25 along the guide shaft 29 to be wound around
the driven pulley 52 disposed near the back surface, whereby the timing
belt 53 is entrained in an L-shape. The driven pulley 52 is rotatably
supported by a pulley holder 55 that is slidable in the axial direction
of the guide shaft 29. The pulley holder 55 is pressed toward the back
surface of the lower frame 25 by a helical torsion coil spring 56.
Receiving this pressing force, an appropriate tension is given to the
timing belt 53 wound around the driven pulley 52. The part of the timing
belt 53 between the driven pulley 52 and the intermediate pulley 54, that
is, the part along the guide shaft 29 is grasped by the belt grasping
portion 48 of the carriage 28. Thereby, the timing belt 53 and the
carriage 28 are coupled together. It is to be noted that as the timing
belt 53, a non-endless belt having both ends thereof fixed to the
carriage 28 may be used as well as an endless belt.

[0053] While in the present embodiment, the CIS 27 is mounted on the
carriage 28 and moved parallel to the platen glass 20 by the belt driving
mechanism 30, the moving means for the line sensor such as the CIS 27 is
not limited thereto; for example, a structure may be adopted such that
the carriage 28 is omitted, the guide shaft 29 directly supports the CIS
27 and the timing belt 53 of the belt driving mechanism 30 is directly
coupled to the CIS 27.

[0054] As shown in FIG. 3, the original cover 4 has the ADF 3 that
continuously conveys the original from an original tray 60 (original
placement portion) by way of a predetermined original conveyance path 61
(conveyance path) to an original output tray 62 (original output
portions). In the process of conveyance by the ADF 3, the original passes
through the moving original reading area 23 on the top surface of the
original table 2, and the image reading unit 24 that is on standby
therebelow reads the image of the original.

[0055] On the top surface of the original cover 4, the original tray 60
and the original output tray 62 are provided one on the other with the
original tray 60 below. The original tray 60 is formed integrally with
the top surface of the original cover 4. The originals from which the ADF
3 performs image reading are placed on the original tray 60 with their
fronts end in the paper feed direction being inserted in the ADF 3 in a
condition where a plurality of sheets are piled up.

[0056] On the original tray 60, a pair of original guides 63 that is apart
in the direction of the width of the image reading device 1 is provided
so as to be slidable in the direction of the width of the device. The
original guides 63 rise from the original tray 60 to restrict the
position, in the direction of the width, of the originals placed on the
original tray 60. The pair of original guides 63 is structured so that
when one original guide 63 is slid, the other original guide 63 is slid
in the opposite direction in synchronization therewith by a known
interlock mechanism.

[0057] In the case of originals of a small width, when one original guide
63 is slid toward the center in the direction of the width of the device,
the other original guide 63 is also slid toward the center in the
direction of the width of the device in synchronization therewith.
Thereby, the original width restricted by the pair of original guides 63
can be reduced with substantially the center in the direction of the
width of the device as the reference. In the case of originals of a large
width, when one original guide 63 is slid outward in the direction of the
width of the device, the other original guide 63 is also slid outward in
the direction of the width of the device in synchronization therewith, so
that the original width restricted by the pair of original guides 63 can
be increased.

[0058] The original output tray 62 is integrally formed on the pair of
original guides 63 so as to be apart in the vertical direction from the
original tray 60. The original outputted from the ADF 3 is held in a
condition of being separated from the originals on the original tray 60
while both sides are supported on the original output tray 62. An
original whose length in the paper output direction is larger than the
original output tray 62 is held on the original tray 60 with its end in
the paper output direction hanging from the original output tray 62.
Consequently, the front end, in the paper output direction, of the
original on the original output tray 62 is situated on the rear end, in
the paper feed direction, of the originals on the original tray 60.
However, since the front end, in the paper feed direction, of the
originals on the original tray 60 and the rear end, in the paper output
direction, of the originals on the original output tray 62 are held so as
to be placed one on the other by the original output tray 62, originals
not read yet and originals already read are never mixed up with each
other. By the original output tray 62 being short, the necessary space on
the original cover 4 can be reduced to thereby reduce the size of the
image reading device 1.

[0059] An extension tray 64 is provided on the end, of the original tray
60, on the side where the ADF 3 is not provided, that is, on the end on
the back side of the device. By its device back side being pivotably
supported, the extension tray 64 is pivotable between an extended
position where it protrudes toward the back side of the original tray 60
and a turned-down position where it is turned down on the top surface of
the original tray 60. By setting the extension tray 64 in the extended
position, originals larger than the original tray 60 can be held by the
original tray 60 and the extension tray 64. Thereby, originals of a size
larger than the original tray 60 can be conveyed by the ADF 3 while
placed on the original tray 60 and the extension tray 64, and the
originals outputted from the ADF 3 can be held by the original output
tray 62, the original tray 60 and the extension tray 64. When an original
of a size not larger than the original tray 60 is read, by setting the
extension tray 64 in the turned-down position, the area of the original
cover 4 can be reduced, so that size reduction of the device is realized.

[0060]FIG. 10 is a longitudinal cross-sectional view showing the internal
structure of the ADF 3. As shown in FIG. 10, in the ADF 3, the original
conveyance path 61 is formed substantially in a U shape when viewed
laterally in a longitudinal cross section, so as to couple the original
tray 60 and the original output tray 62 together. The original conveyance
path 61 comprises an ADF body 65 formed integrally with the original
cover 4 and an ADF cover 66 openable and closably provided on the ADF
body 65. An admission chute 67 of the ADF 3 is formed so as to extend the
original placement surface of the original tray 60. The admission chute
67 is vertically formed as a passage of a predetermined width with the
following as guide surfaces: a guide plate 68 formed integrally with the
ADF body 65; and a partitioning plate 69 disposed inside the ADF cover
66. The originals from which the ADF 3 performs image reading are placed
on the original tray 60 with their front ends in the paper feed direction
being inserted in the admission chute 67.

[0061] The original conveyance path 61 forms a so-called U-turn path from
the admission chute 67 by way of a bent portion 70 to a paper output
chute 71. The bent portion 70 and the paper output chute 71 are also
continuously formed as a passage of a predetermined width by the ADF body
65, the ADF cover 66, the partitioning plate 69, and the like. The
original set on the original tray 60 is fed to the bent portion 70 by
being guided by the admission chute 67, and is outputted from the paper
output chute 71 to the original output tray 62, whereby the original is
conveyed from the original tray 60 to the original output tray 62 so as
to be reversed.

[0062] An admission roller 72 and an admission nip member 73 pressed
thereagainst, a separation roller 74 and a separation nip member 75
pressed thereagainst, and an original conveyance roller 76 and pinch
rollers 77 pressed thereagainst are disposed on the original conveyance
path 61. While these components constitute the conveying means for
conveying the original, the structures of the rollers and the nip members
are merely an example, and it is to be noted that the number of rollers
and the disposition may be changed or the conveying means may be changed
to different known conveying means such as using pinch rollers instead of
the nip members.

[0063] The admission roller 72 is rotatably provided substantially in the
center of the admission chute 67 so that part of its roller surface is
exposed from the top surface of the guide plate 68. Likewise, the
separation roller 74 is rotatably provided in a position apart from the
admission roller 72 in the paper feed direction so that part of its
roller surface is exposed from the top surface of the guide plate 68. The
admission roller 72 and the separation roller 74 are rotated by receiving
the driving force from the motor. The admission roller 72 and the
separation roller 74 which have the same diameter are rotated at the same
circumferential velocity. In the driving transmission to the admission
roller 72, a one-rotation clutch is interposed, and the admission roller
72 can run idle by an amount corresponding to one rotation.

[0064] The admission nip member 73 is provided in a position opposed to
the admission roller 72 of the partitioning plate 69 so as to be
swingable in directions in which it comes into contact with and separates
from the admission roller 72. The admission nip member 73 is in the form
of a pad whose width is slightly smaller than the roller width, in the
axial direction, of the admission roller 72. The admission nip member 73
is rotatably supported by the partitioning plate 69 with its both ends in
the upstream side in the paper feed direction as the rotation axis,
whereby the end on the downstream side in the paper feed direction moves
backward and forward so that it can come into contact with the roller
surface of the admission roller 72. The admission nip member 73 is
resiliently pushed downward by a spring member, and is pressed against
the admission roller 72 at all times in a condition of not nipping the
original. Although a roller may be used instead of the pad-form admission
nip member 73, by using a pad-form abutting member, a simple and
space-saving abutting member can be realized, and the adjustment of the
resilient pushing force applied to the abutting member is easy.

[0065] The separation nip member 75 is provided in a position opposed to
the separation roller 74 of the partitioning plate 69 so as to be
swingable in a direction in which it comes into contact with and
separates from the separation roller 74. The separation nip member 75 is
in the form of a pad whose width is slightly smaller than the roller
width, in the axial direction, of the separation roller 74. The end, on
the downstream side in the paper feed direction, of the separation nip
member 75 moves backward and forward so that it can come into contact
with the roller surface of the separation roller 74 with its upstream
side in the paper feed direction as the rotation axis. The separation nip
member 75 is resiliently pushed downward by a spring member, and is
pressed against the roller surface of the separation roller 74 at all
times in a condition of not nipping the original. Although a roller may
be made to abut on the separation roller 74 instead of the pad-form
separation nip member 75, by using a pad-form abutting member, a simple
and space-saving abutting member can be realized, and the adjustment of
the resilient pushing force applied to the abutting member is easy.

[0066] The original conveyance roller 76 is disposed at the bent portion
70, formed substantially in a U shape when viewed laterally, of the
original conveyance path 61. The original conveyance roller 76 has an
outer diameter such that its roller surface constitutes part of the bent
portion 70. Like the admission roller 72 and the separation roller 74,
the original conveyance roller 76 is rotated by receiving the driving
force from the motor.

[0067] The pinch rollers 77 are provided in three positions around the
original conveyance roller 76. The pinch rollers 77 are each rotatably
supported by the ADF body 65 or the ADF cover 66 by its shaft being
resiliently pushed by a spring member, and are pressed against the roller
surface of the original conveyance roller 76. When the original
conveyance roller 76 rotates, the pinch rollers 77 also rotate in
synchronization therewith. The pinch rollers 77 press the original
against the original conveyance roller 76, thereby transmitting the
rotating force of the original conveyance roller 76 to the original.

[0068] The paper output chute 71 is formed on the downstream side in the
paper feed direction of the original conveyance roller 76. The paper
output chute 71 is formed between the ADF cover 66 and the partitioning
plate 69 so as to be continuous with the bent portion 70 of the original
conveyance path 61 constituted by the inner surface of the ADF cover 66
and the original conveyance roller 76. The original fed from the original
tray 60 to the original conveyance path 61 passes through the admission
chute 67, the bent portion 70 and the paper output chute 71, and is
outputted onto the original output trays 62.

[0069] The ADF cover 66 is provided so as to be upwardly rotatable with
its original tray 60 side from the admission roller 72 as the rotation
axis. By opening the ADF cover 66, the guide plate 68 and the
partitioning plate 69 are largely separated from each other, so that the
admission chute 67 and the bent portion 70 are opened and the admission
roller 72 and the separation roller 74, and the admission nip member 73
and the separation nip member 75 are largely separated from each other.
By opening the ADF cover 66, paper jams occurring on the original
conveyance path 61 can be cleared, and maintenance of the inside of the
ADF 3 can be performed.

[0070] The image reading operation by the image reading device 1 will be
described with reference to FIGS. 11 and 12. FIGS. 11 and 12 are plan
views showing the top surface of the original table 2. In the figures,
the original cover 4 and the operation panel 5 are omitted. As shown in
the figures, the stationary original reading area 22 and the moving
original reading area 23 are formed on the original table 2. While the
side where the moving original reading area 23 is formed is the front
side of the device, the position of the moving original reading area 23
is changed as appropriate according to whether the ADF 3 is provided on
the device front side or the device back side of the original cover 4.

[0071] As shown in FIG. 11, when the image reading device 1 is used as an
FBS, the original is placed on the stationary original reading area 22.
The maximum original size that can be placed on the stationary original
reading area 22 is A4 size. The area 80 indicated by the chain
double-dashed line shown in the figure represents an area equal to A4
size. As shown in the figure, an A4-size original is placed with the
direction of the length thereof as the direction of the length of the
stationary original reading area 22, that is, the direction of the width
of the device.

[0072] The CIS 27 is incorporated in the original table 2. As shown in the
figures, the CIS 27 is a line sensor that is elongated in the direction
of the length of the stationary original reading area 22 and whose
reading line is the direction of the length of its elongated shape. The
reading line of the CIS 27 is substantially the same in width as the
direction of the length of the stationary original reading area 22, and
corresponds to the length in the direction of the length of A4-size
originals. When image reading is started, the CIS 27 is moved to one end
in the direction of the width of the stationary original reading area 22,
for example, to the side of the moving original reading area 23 by the
belt driving mechanism 30 described previously. Then, the CIS 27 is moved
to the other end of the stationary original reading area 22, for example,
to the back side of the device while emitting light from the light source
and receiving the light reflected from the original. That is, the CIS 27
is moved in the direction of the width of the stationary original reading
area 22. During this movement, the reflected light successively received
by the CIS 27 is converted into an electric signal and outputted, and
with the direction of the length of the stationary original reading area
22 as the reading line, image reading from the original is performed.
That is, the CIS 27 performs image reading from the original with the
direction of the length of the stationary original reading area 22 as the
main scanning direction and the direction of the width thereof as the sub
scanning direction. Further, in other words, the image reading from
A4-size originals is performed with the direction of the length thereof
as the main scanning direction and the direction of the width thereof as
the sub scanning direction. Thereby, the distance by which the CIS 27 is
moved is short compared with when image reading is performed by a line
sensor with the direction of the width of the stationary original reading
area 22 as the main scanning direction and the direction of the length
thereof as the sub scanning direction, so that the movement time of the
CIS 27 is reduced. In particular, since the return time to return the CIS
27 to the standby position after original reading is reduced, the time
required for image reading is reduced.

[0073] FIG. 12 depicts the movement of the original with respect to the
original table 2 when the ADF 3 is used. When the ADF 3 is used, as shown
in FIG. 12, the CIS 27 is moved and stopped below the moving original
reading area 23. The original to be read is placed on the original tray
60 of the ADF 3. The width of the original conveyance path 61 of the ADF
3 corresponds to the direction of the length of the moving original
reading area 23. The length in the direction of the length of the moving
original reading area 23 is equal to the length in the direction of the
length of the stationary original reading area 22, and corresponds to the
length in the direction of the length of A4-size originals. The ADF 3 is
capable of conveying originals of widths of up to the width of the
original conveyance path 61. That is, it is capable of conveying
originals whose length in the direction of the width is the length in the
direction of the length of A4-size originals. The originals of the
standard size having such a width are of A3 size. Thus, the ADF 3 is
capable of conveying A3-size originals with the direction of the length
of the original as the conveyance direction.

[0074] The top surface of the original table 2 is slightly larger than A4
size, and approximately the same as the two-dimensional area of the
original cover 4. Therefore, although when an A3-size original is placed
on the original tray 60 formed on the top surface of the original cover
4, part of the A3-size original lies outside the original cover 4, it can
be held on the original cover 4 by setting the extension tray 64 in the
extended position. The A3-size original placed on the original tray 60
and the extension tray 64 is fed to the original conveyance path 61 and
reaches the moving original reading area 23. By being further conveyed,
the original passes through the moving original reading area 23. At that
time, the CIS 27 reads the image of the original being conveyed.

[0075] The area 81 indicated by the chain double-dashed line in FIG. 12
represents an A3-size original. As shown in the figure, the direction in
which the A3-size original passes through the moving original reading
area 23 is a direction orthogonal to the direction of the length of the
moving original reading area 23. The direction of the length of the
moving original reading area 23 and the direction of the reading line of
the CIS 27 are the same. That is, the direction of the length of the
moving original reading area 23 is the main scanning direction of the CIS
27, and the original conveyance direction is the sub scanning direction
of the CIS 27. Therefore, image reading from A3-size originals conveyed
by the ADF 3 is performed with the direction of the width thereof as the
main scanning direction and the direction of the length thereof as the
sub scanning direction. Thereby, image reading from originals of widths
that lie within the length of the moving original reading area 23, that
is, originals of up to A3 size can be performed.

[0076] As described above, according to the image reading device 1, since
the stationary original reading area 22 that is rectangular when viewed
two-dimensionally and the moving original reading area 23 disposed along
the direction of the length of the stationary original reading area 22
are formed on the top surface of the original table 2 and the CIS 27
provided in the original table 2 performs image reading from the original
placed on the stationary original reading area 22 with the direction of
the length of the stationary original reading area 22 as the main
scanning direction and the direction of the width thereof as the sub
scanning direction, the movement width of the CIS 27 with respect to the
stationary original reading area 22 is reduced. Moreover, since in the
moving original reading area 23, the original is conveyed by the ADF 3 in
the direction orthogonal to the direction of the length of the moving
original reading area 23 and image reading from the conveyed original is
performed with the direction of the length of the moving original reading
area 23 as the main scanning direction of the CIS 27 and the conveyance
direction as the sub scanning direction, image reading from originals of
widths that lie within the length of the moving original reading area 23
is performed. Thereby, image reading from originals of large sizes that
cannot be placed on the stationary original reading area 22 corresponding
to A4 size, for example, A3 size can be performed.

[0077] While a case where the CIS 27 is used as the line sensor is shown
in the present embodiment, the line sensor is not limited to the CIS; for
example, a so-called image reading unit of a reduction optical system
that reduces the image of the original by a reflecting mirror, a lens and
the like and focuses it on a CCD (charge coupled device) by using the CCD
as the line sensor may be used.

[0078] Moreover, while in the present embodiment, the ADF 3 of a U-turn
path is shown in which the original tray 60 and the original output tray
63 are placed one on the other on the original cover 4 with the original
tray 60 below and the original is conveyed from below to above so as to
be reversed, it is to be noted that similar effects are obtained when a
change is made to a U-turn path in which the positional relation between
the original tray 60 and the original output tray 63 is vertically
reversed so that the original is conveyed from above to below.

[0079] Instead of the ADF 3 of the U-turn path in which the original is
conveyed so as to be reversed like in the present embodiment, an ADF of a
straight path may be used. Specifically, as shown in FIG. 13, an ADF 6 of
a straight path is disposed on the original cover 4. On the original
table 2, like in the above-described embodiment, the platen glass 20 is
exposed from the top surface thereof, and the stationary original reading
area 22 and the moving original reading area 23 are formed. Moreover, the
image reading unit 24 is incorporated in the original table 2.

[0080] As shown in FIG. 13, the original cover 4 has an ADF 6 that
continuously conveys the original from an original tray 101 (original
placement portion) by way of a predetermined original conveyance path 102
(conveyance path) to an original output tray 103 (original output
portion). In the process of conveyance by the ADF 6, the original passes
through the moving original reading area 23 of the platen glass 20, and
the image reading unit 24 that is on standby therebelow reads the image
of the original.

[0081] The original tray 101 is formed integrally with the top surface of
the original cover 4. The originals from which the ADF 6 performs image
reading are placed on the original tray 101 with their front ends in the
paper feed direction being inserted in the ADF 6 in a condition where a
plurality of sheets are piled up. While the original tray 101 has
original guides like in the above-described embodiment, they are not
shown in the figure. An extension tray 104 is provided on the end, of the
original tray 101, on the side where the ADF 6 is not provided. The
extension tray 104 is similar to the extension tray 64, and by the end of
the original tray 101 being pivotably supported, the extension tray 104
is pivotable between an extended position where it protrudes from the
original tray 101 and a turned-down position where it is turned down on
the top surface of the original tray 101.

[0082] The original output tray 103 is disposed in a position opposed to
the original tray 101 with the moving original reading area 23 in between
so as to protrude slightly upward from the horizontal from a side surface
of the original table 2. The original output tray 103 holds the originals
outputted from the ADF 6. The original output tray 103 is capable of
holding originals of up to the maximum size that can be conveyed by the
ADF 6, specifically, originals of up to A3 size, the size of the original
output tray 103 can be reduced by making the original output tray 103
approximately as large as originals of A4 size and providing an extension
tray similar to the extension tray 104. The ADF 6 may be disposed either
on the front side or the back side of the device, and in correspondence
therewith, the original output tray 103 may also be disposed either on
the front side or the back side of the device.

[0083] In the ADF 6, the original conveyance path 102 is formed so as to
couple the original tray 101 and the original output tray 103 together.
The original conveyance path 102 is a straight path leading from an
admission chute 105 by way of the moving original reading area 23 to the
original output tray 103. The original is straightly conveyed from the
original tray 101 to the original output tray 103 along the original
conveyance path 102.

[0084] An admission roller 106 and an admission nip member 107 pressed
thereagainst, a separation roller 108 and a separation nip member 109
pressed thereagainst, an original conveyance roller 110 and pinch rollers
111 pressed thereagainst, and a paper output roller 112 and a pinch
roller 113 pressed thereagainst are disposed on the original conveyance
path 102. Since these components are similar to those of the
above-described embodiment, detailed descriptions thereof are omitted.
While these components constitute the conveying means for conveying the
original, the structures of the rollers and the nip members are merely an
example, and it is to be noted that the number of rollers and the
disposition may be changed or the conveying means may be changed to
different known conveying means such as using pinch rollers instead of
the nip members.

[0085] When image reading from originals is performed by such an ADF 6,
like in the above-described embodiment, the CIS 27 is moved and stopped
below the moving original reading area 23 (see FIG. 12). The original to
be read is placed on the original tray 101 of the ADF 6. The width of the
original conveyance path 102 of the ADF 6 corresponds to the direction of
the length of the moving original reading area 23, and originals whose
length in the direction of the width is the length in the direction of
the length of originals of A4 size, specifically, originals of A3 size
can be conveyed with the direction of the length of the originals as the
conveyance direction.

[0086] The direction in which A3-size originals conveyed by the ADF 6 pass
through the moving original reading area 23 is a direction orthogonal to
the direction of the length of the moving original reading area 23. That
is, the direction of the length of the moving original reading area 23 is
the main scanning direction of the CIS 27, and the original conveyance
direction is the sub scanning direction of the CIS 27. Therefore, image
reading from A3-size originals is performed with the direction of the
width thereof as the main scanning direction and the direction of the
length thereof as the sub scanning direction. Thereby, image reading from
originals of widths that lie within the length of the moving original
reading area 23, that is, originals of up to A3 size can be performed. As
described above, effects similar to those of the above-described
embodiment are obtained when the ADF 6 of the straight path is used
instead of the ADF 3.

Second Embodiment

[0087] Hereinafter, a second embodiment will be described. While in the
above-described first embodiment, the original cover 4 having the ADF 3
is openably and closably provided on the original table 2 so as to cover
both the stationary original reading area 22 and the moving original
reading area 23, in the second embodiment, an original cover 10 is
openably and closably provided on the original table 2 so as to cover
only the stationary original reading area 22, and a principal part such
as the conveying means of an ADF 9 is provided independently of the
original cover 10.

[0088]FIG. 14 is a perspective view showing the external structure of an
image reading device 7 according to the second embodiment. In the image
reading device 7, the ADF 9 is provided above an original table 8
functioning as an FSB, and the original cover 10 (cover member)
constituting part of the ADF 9 is openably and closably attached to the
original table 8.

[0089] An operation panel 11 is provided on the front side of the image
reading device 7. The operation panel 11 is similar to the operation
panel 5, and has various operation keys and a liquid crystal display. The
image reading device 7 operates not only on instructions inputted to the
operation panel 11 but also on instructions transmitted, when the image
reading device 7 is connected to a computer, from the computer through
the scanner driver.

[0090] FIG. 15 shows the image reading device 7 in a condition where the
original cover 10 is opened with respect to the original table 8. As
shown in the figure, a platen glass 120 (transparent member) is disposed
on the top surface of the original table 8. The area where the platen
glass 120 is exposed from the top surface of the original table 8 is a
stationary original reading area 121. The stationary original reading
area 121 is an area where the original is placed and read when the image
reading device 7 is used as a flatbed scanner.

[0091] FIG. 16 is a plan view of the original table 8 where the original
cover 10 and the operation panel 11 are omitted. As shown in the figure,
a moving original reading area 122 is provided on the device back side of
the stationary original reading area 121 and immediately below the ADF 9.
The moving original reading area 122 is an area where the original passes
when image reading is performed by using the ADF 9 of the image reading
device 7. The hatched area shown in the figure is the area not exposed
even when the original cover 10 is opened. That is, the original cover 10
covers only part of the stationary original reading area 121, and is not
opened or closed with respect to the moving original reading area 122.
Although not shown, a pressing member comprising a sponge, a white board
and the like is disposed on the lower surface of the original cover 10 in
order to press the original placed on the stationary original reading
area 121.

[0092] The stationary original reading area 121 is rectangular when viewed
two-dimensionally, and occupies most of the top surface of the original
table 8. The direction of the length of the stationary original reading
area 121 is the direction of the width of the device. The maximum size
that can be placed on the stationary original reading area 121 is A4
size. That is, when used as an FBS, the image reading device 7 can read
originals of up to A4 size. A4-size originals are placed on the platen
glass 120 with reference to the front side of the device so that the
direction of the length thereof coincides with the direction of the
length of the stationary original reading area 121, that is, with the
direction of the length of the originals as the direction of the width of
the device.

[0093] The moving original reading area 122 is formed on the device back
side of the stationary original reading area 121. The moving original
reading area 122 is an area elongated in the direction of the length of
the stationary original reading area 121. When image reading is performed
by using the ADF 9 of the image reading device 7, the original is
conveyed so as to pass through the moving original reading area 122.

[0094] An image reading unit is incorporated in the original table 8. In
the image reading by the FBS, a CIS 126 constituting the image reading
unit is reciprocated along the platen glass 120 to thereby perform image
reading from the original placed on the stationary original reading area
121. When the ADF 9 is used, the CIS 126 moves to a position where the
original passing through the moving original reading area 122 can be
read, and stops. Since such an image reading unit is similar to the image
reading unit 24 described in the first embodiment, a detailed description
thereof is omitted.

[0095] As shown in FIG. 14, the ADF 9 continuously conveys the original
from an original tray 123 (original placement portion) by way of a
predetermined original conveyance path to an original output tray 124
(original output portions). In the process of conveyance by the ADF 9,
the original passes through the moving original reading area 122 on the
top surface of the original table 8, and the CIS 126 that is on standby
therebelow reads the image of the original. The original cover 10 has, on
its top surface, part of the ADF 9, that is, the original tray 123 and
the original output tray 124. In other words, the original conveyance
path, the conveying means and the like of the ADF 9 are formed
independently of the original cover 10. Therefore, although the original
tray 123 and the original output tray 124 rotate together with the
original cover 10 as the original cover 10 is opened and closed, the
original conveyance path, the conveying means and the like of the ADF 9
are stationary irrespective of the opening and closing of the original
cover 10. Since the internal structure of the ADF 9 is similar to that of
the ADF 3 described in the first embodiment, a detailed description
thereof is omitted. Although not shown, an extension tray similar to the
extension tray 104 may be provided on the original tray 123.

[0096] When the image reading device 7 is used as an FBS, as shown in FIG.
15, the stationary original reading area 121 is exposed by opening the
original cover 10. Then, the original is placed on the stationary
original reading area 121. The stationary original reading area 121 is
formed with the maximum placeable size as A4 size, and the area 125
indicated by the chain double-dashed line shown in FIG. 16 represents an
area equal to A4 size. Although the area, on the device back side, of the
stationary original reading area 121 (the hatched area of FIG. 16) is not
exposed, an A4-size original can be placed on the stationary original
reading area 121 by slipping the original from the exposed device front
side.

[0097] The CIS 126 of the image reading unit is incorporated in the
original table 8. As shown in the figures, the CIS 126 is a line sensor
that is elongated in the direction of the length of the stationary
original reading area 121 and whose reading line is the direction of the
length of its elongated shape. The reading line of the CIS 126 is
substantially the same in width as the direction of the length of the
stationary original reading area 121, and corresponds to the length in
the direction of the length of A4-size originals. When image reading is
started, the CIS 126 is moved in the direction of the width from the
front side of the stationary original reading area 121 by a belt driving
mechanism. During this movement, the CIS 126 emits light from the light
source, receives the light reflected from the original, converts the
received reflected light into an electric signal, and outputs them.
Thereby, image reading from the original is performed with the direction
of the length of the CIS 126 as the reading line. That is, the CIS 126
performs image reading from the original with the direction of the length
of the stationary original reading area 121 as the main scanning
direction and the direction of the width thereof as the sub scanning
direction. Further, in other words, the image reading from A4-size
originals is performed with the direction of the length thereof as the
main scanning direction and the direction of the width thereof as the sub
scanning direction. Thereby, the distance by which the CIS 126 is moved
is short compared with when image reading is performed by a line sensor
with the direction of the width of the stationary original reading area
121 as the main scanning direction and the direction of the length
thereof as the sub scanning direction, so that the movement time of the
CIS 126 is reduced.

[0098]FIG. 17 depicts the movement of the original with respect to the
original table 8 when the ADF 9 is used. When the ADF 9 is used, as shown
in FIG. 14, the original cover 10 is closed with respect to the original
table 8. Then, as shown in FIG. 17, the CIS 126 is moved and stopped
below the moving original reading area 122. The original to be read is
placed on the original tray 123 of the ADF 9. The width of the original
conveyance path of the ADF 9 corresponds to the direction of the length
of the moving original reading area 122. The length in the direction of
the length of the moving original reading area 122 is equal to the length
in the direction of the length of the stationary original reading area
121, and corresponds to the length in the direction of the length of
A4-size originals. The ADF 9 is capable of conveying originals of widths
of up to the width of the original conveyance path. That is, it is
capable of conveying originals whose length in the direction of the width
is the length in the direction of the length of A4-size originals. The
originals of the standard size having such a width are of A3 size. Thus,
the ADF 9 is capable of conveying A3-size originals with the direction of
the length of the originals as the conveyance direction.

[0099] The A3-size original placed on the original tray 123 is fed to the
original conveyance path and reaches the moving original reading area
122. By being further conveyed, the original passes through the moving
original reading area 122. At that time, the CIS 126 reads the image of
the original being conveyed.

[0100] The area 127 indicated by the chain double-dashed line in FIG. 17
represents an A3-size original. As shown in the figure, the direction in
which the A3-size original passes through the moving original reading
area 122 is a direction orthogonal to the direction of the length of the
moving original reading area 122. The direction of the length of the
moving original reading area 122 and the direction of the reading line of
the CIS 126 are the same. That is, the direction of the length of the
moving original reading area 122 is the main scanning direction of the
CIS 126, and the original conveyance direction is the sub scanning
direction of the CIS 126. Therefore, image reading from A3-size originals
conveyed by the ADF 9 is performed with the direction of the width
thereof as the main scanning direction and the direction of the length
thereof as the sub scanning direction. Thereby, image reading from
originals of widths that lie within the length of the moving original
reading area 122, that is, originals of up to A3 size can be performed.

[0101] As described above, similar workings and effects to those of the
above-described first embodiment are obtained by the image reading device
7. Moreover, by a structure like the present embodiment that the original
cover 10 covers only the stationary original reading area 121, only the
original tray 123 and the original output tray 124 constituting part of
the ADF 9 rotate as the original cover 10 is opened and closed, the
remaining components of the ADF 9 such as the original conveyance path
and the conveying means provided above the moving original reading area
122 are stationary above the original table 8 independently of the
original cover 10, the weight of the original cover 10 is reduced, so
that the opening and closing of the original cover 10 is facilitated. In
addition, since the shock and vibrations incident to the opening and
closing of the original cover 10 are not directly transmitted to the
driving portion such as the conveying means of the ADF 9, the failure of
the ADF 9 can be reduced.

[0102] In the present embodiment, an image reading unit of a reduction
optical system using a CCD may also be used instead of the CIS 126.
Moreover, it is to be noted that in the ADF 9, a change may be made to a
U-turn path in which the positional relation between the original tray
123 and the original output tray 124 is vertically reversed so that the
original is conveyed from above to below so as to be reversed or a
straight path may be used instead of the U-turn path.

[0103] As this invention may be embodied in several forms without
departing from the spirit of essential characteristics thereof, the
present embodiment is therefore illustrative and not restrictive, since
the scope of the invention is defined by the appended claims rather than
by the description preceding them, and all changes that fall within metes
and bounds of the claims, or equivalence of such metes and bounds thereof
are therefore intended to be embraced by the claims.